Telephone-exchange system.



E. S. BROWNING. TELEPHONE EXCHANGE SYSTEM. I APPLICATION FILED J'ULY18,1913. RENEWED JAIL-19, 1915. 7 1,129,951. Patented r- 2, 1915.

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E. BROWNING.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION I'ILBD JULY 18, 1913. RENEWED JAN.1\J. 1915. 1,129,951,Patented Mar.,2,1915.

3 SHEETS-SHEET Z.

Brown [129 E. S...B.ROWNING. TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED JULY 18, 1913. RENEWED JAN. 19, 1915.

1 129 951 Patented M212, 1915.

3 SHEETS-SHEET 3.

61 now;

ESTHER. S. BROW'NING. 0F KEEFETON, OKLAHDMA.

TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent.

Patented Mar. 2, 1915.

Application filed July 18. 1913. Serial No. 779.778. Renewed January 19,1915. Serial No. 3,169.

To all whom it may concern Be it known that I. ESTHER S. BRowMNu, acitizen of the United States, residing at Keefeton. in the county ofMuskogee and State of Oklahoma, have invented new and usefulImprovements in Telephone EX- change Systems. of which the following isa specification.

This invention relates to improvements in exchange systems for telephonelines and the like and has particular application to an exchange systemfor use in railroad signal towers, oiiices and other analogous placeswhereby any one of a plurality of incoming lines may be connected upwith any one of a number of locals.

In carrying out the present invention, it is my purpose to provide anexchange system of the class described wherein the use of corded plugsand cooperating spring jacks may be eliminated and whereby it will beimpossible for the operator in charge of the exchange telephone set tolisten in when the particular incoming and local lines are connected up.

It is also my purpose to provide an exchange system for telephone linesand the like which will embody among other features a plurality ofincoming transmission lines, and a number of local lines. means beingprovided and operable to connect any one of the incoming lines to anexchange operators telephone set so that such operator may ascertain thelocal that the party talking over the incoming line wishes to havetalking communication with, means being employed and operable to connectthe incoming line to the desired local line when the operator in chargeof the exchange set has ascertained such local.

Furthermore, I aim to provide an exchange system of the class describedwherein by means of a plurality of levers. one connected to the terminalof each incoming line. and a plurality of contacts forming the terminalsof the locals and adapted to be engaged by the levers. any one of theincoming lines may be connected with the desired local line so thattalking communication between such lines will be established.

With the above and other objects in view. the invention consists in theconstruction. combination and arrangement of parts hereinafter set forthin and falling within the scope of the claims.

In the accompanying drawings: Figure l is a view in front elevation of aswitch board constructed in accordance with my present invention. Fig. 2is a vertical sectional view through the board. Fig. 3 is a view in sideelevation of the contact member carried by each lever. Fig. l is a planview of a detail of the invention. Fig. 5-is a fragmentary view ofanother detail of the invention, and Fig. 6 is a diagrammatic view ofthe exchange system. v

leferring now to the accompanying drawings in detail, S designates aconventional switch board structure having a breast plate 1 construct-edof suitable material and formed with transverse slots '2 appropriatelyspaced apart along'the length of the plate. Suitably secured to the baseof the switch board structure below the breastplate 1 are binding posts3 spaced apart and each disposed in alinement with one'ot the slots :2in the breast plate. The binding posts 3 are passed through slots formedin the horizontal limbs of angle brackets i seated upon the base of theswitch board and extending upwardly therefrom and having laterallyprojecting ears 5, 5 formed integral with the free ends of the verticallimbs thereof and suitably spaced apart, as illustrated in Fig. l. Thecars 5, 5 of each bracket are formed with alining elongated slots 6designed to slidably receive a pin 7 and fulcru ned upon each pin 7between the respective pair of cars and projecting through the aliningslot (5 in the breast plate is a lever 8 having the lower end thereofscrew threaded to receive a nut 9 against which bears one end of acoiled expansion spring 10 surrounding the lower end of the lever belowthe fulcrum thereof, the free extremity of such spring bearing against acollar 11 loosely surrounding the lower port-ion of the lever andabutting the ears 5. 5. Formed in the breast plate 1 upon one side ofeach slot 2 therein is a series of depressions 12 suitably spaced apartand receiving contacts 13 having shanks 14- projecting through aperturesformed in the lower walls of the depressions. the free extremities ofsuch shanks being screw threaded to receive nuts 15 cooperating with theshanks.- to form binding posts; Passed through each lever adjacent tothe upper endtl'iereof aboz'e the breast plate is a pivot pin 16 uponwhich is concentrically mounted a disk arranged JOQ mas er uponlone sideof the lever and formedu'pon its periphery with a radially extending lug18 adapted to enter one or the other of engage the rear edge of thelever when the 1' lug 18 is seated upon the contact in the respectivedepression, as illustrated 111 Fig. 2, whereby further'swinging movementof the lever 8 about its fulcrum is prevented. is

Extending outwardly from the periphery of the disk at a pointadjacent tothe stop lug 19 is a manipulating finger by means of which the disk maybe rotated about its pivot so as to throw the lever rearwardly a slightdistance and so permit the lug 18 to be withdrawn from the depression.From this construction, it will be seen that when the lug 18 is engagedin one of the depressions of the respective series, the lever -8 will bemoved in an upward direction against the action of the spring 10,thereby enabling the spring to react andhold the locking lug 1 9 infrictional engagement with the respective edge of the lever so thataccidental displacement of the lever is avoided. On the other hand, whenthe disk 17 is swung about its pivot point under the ac tion of themanipulating finger 20, the lug 18 will ride out of the respectivedepression and so permit the spring 10 to expand and force the lever 8downward y whereby the periphery of the disk will frictionally engagethe adjacent portion of the breast plate, Leading into the switch boardS are a plurality of incoming transmission lines 21 each terminallyconnected to one of the binding posts 3. The uppermost contacts of thesets aline longitudinally of the breast plate as illustrated in thediagrammatic view, while the remaining contacts of the sets aresimilarly arranged, and conthe top contact of each series or nected toset i: 1: -'--i..c ?rto 22- extending through the coil of the magnet ofa drop 23 arranged upon the switch board 'above the respective set orseries of contacts, the free terminals of the windings of the magnets ofthe drops being tapped ODLO a common return wire or conductor 2igrounded as at '25. Normally, the levers 8 are in the up position asillustrated in Figs. 1 andZ so that the contacts 3 and the upper contact13 oi the various sets or rows are-bridged by means of the levers. Fromthis it will be seen that when the receiver of a telephone set connectedin one of the lines :21 is removed from the hook the circuit willbeclosed to tb. respective drop 23 thereby notifying he operator in.charge of the switch board or exchange of the particular line calllng.

Leading'from the switch board- S arelo cal lines 26 each including inseries a olear-out drop-fifi located-upon the switch board within thevision of the exchan e" operator, eaciiflocal extending through therespective longitudinally alining contacts of the sets, asillustrated'in Fig. 6. Located in each local" line 26 is a single polodouble throw switch 28' adapted when in one position to close thelocaLthrough the contacts and when in an opposite position to connectthe local line to one side of theexchange operators telephone set 29,the opposite side of such set'being tapped onto the, ground wire 2 L Amagneto generator 30 located upon the switch board within convenientreach of the operator has one side grounded and the opposite sideconnected'to the local lines 26. 7

From the foregoing description takenin connection with the accompanyingdrawlngs, the construction, mode of operation and manner ofemploying myinvention will be readily apparent, been actuated as previouslydescribed, the operator in charge of the switch board breaks the circuitthrough the drop by retating the disk 19 on' the respective lever 8todisengage the lug 18- from the particularcontact and moves such leverdownwardly within the slot 2 so as to engage the luglS- with the nextadjacent contactoit the respective series or set. This manipulation ofthe lever and disk 17 closes the circuit from the respectivetransmission line 21 through a portion of the line conductor 26, theswitch 28 and the exchange operators telephone set 29 thereby enablingthe party on the transmission line to have talking communication withthe operator in charge of the exchange. After the operator in charge ofthe exchange has ascertained which local is desired, the respectivelever 8 is swung about its fulcrum Whena drop 23 has so as to engage thelug 18 on the disk 17 with In the present instance, I have shown avtelephone exchange system having a capacity of six incomingtransmission lines and three local lines and in this connection I wishit to be understood that the capacity of the system may be changed orvaried to suit the requirements an exigencies of each portionlar case.

It will be observed that each one of the lovers will establishcommunication between th v particular transmission line and any one ofthe locals, while by means of the single pole double throw switches 28the electrical continuity of the locals is established and communicationbetween the transmission lines and an exchange operatorslset brokensimultaneously, thereby preventing the c inseam ator in charge of s chhe course of the con hangs operators telephone set and in turn connectedwith the desired outgonig' local While it is impossible, so as myinvention is concerned, to connect one of the local l s 26 with theexchan e operators telephone set zlt As previously stated, my improvedtelephone exchange system is particularly adapted for use in railroadingand the transmission lines 21 come into the switch board from thedespatchers ofiice, While the outgoing local lines 26 lead to thevarious stations along the trackway. Thus, it will be seen that anytelephone set in the despatchens office may be connected up with any oneof the signal toive which the local lines lead. tion has ceased and thereceivers .oi the respective telephone sets are hung up, the particularclearing out drop 2? is actuated to notify the operator that theconnection be ween the lines may be broken.

While l have herein shown and described one pier-erred form of myinvention by Way of illus ration, I wish it to be understood that I donot limit or confine myself to the precise details of constructionherein del and delineated, as modification and nay be made Within thescope of thout do; n c, from spirit l clai and spaced apart adjacent toeach slot and iorming the terminals of certain circuits, loversfulcrumed upon said switch board and movable through the slots in saidbreast plate and disks pivoted upon the upper ends of said levers andformed with lugs to engage said contacts.

2. A telephone switch board comprising a breast plate formed withtransverse slots therein, contacts carried'by said plate and spacedapart adjacent to each slot and forming the terminals of certaincircuits, levers fulcrumed upon said switch board and connected withtheterminals of other circuits and movable through the slots in saidbreast plate, disks pivoted upon the upper ends of said levers andformed with lugs adapted to engage said contacts and means for holdingsaid levers against accidental movement.

3. A telephone switch board comprising a breast plate having transverseslots formed therein, contacts carried by said plate and spaced apartadjacent to each slot and forming the terminals of certain circuits,levers fulcrumed upon said switch board and con nected with theterminals of other circuits and movable through the slots in said breastplate, disks pivoted upon the upper ends of said levers and formed withlugs adapted to engage said contacts, and a lug projecting outwardlyfrom each disk and adapted to engage the adjacent lever end to hold thelever against accidental movement.

testimony whereof l afiix my signature in presence oi two witnesses.

ESTHER S. BROWNING. Witnesses N. H. Jisricn, OMAR "WELLS.

